Calculating Flowrate Using Pressure

[emanager]

Is there a formula to calculate flowrate (gallons per minute) for a 6 inch diameter chilled water pipe if I only have 2 values for pressure - 45 psi and 75 psi. Thanks.

 

[MintJulep]

If it were electricity, would there be a way for you to calculate current in a wire if you only had two values of voltage?

 

[KiwiMace]

I could estimate the pressure drop for you.

 

[katmar]

You will need the length of the pipe between the 2 points where you have measured the pressure. Strictly you need the "equivalent length" which would take into account bends, valves etc but if it is a long simple line you can ignore those for a first estimate.

You also need to adjust the pressure difference for any changes in height because you need the pressure drop due to friction only.

This was discussed recently and I posted the formulas and procedures there. See thread378-235298

Katmar Software
Engineering & Risk Analysis Software

http://katmarsoftware.com

 

[sailcat753]

Go to a fluid dynamics book and research the Bernoulli equation which uses static pressure of two points, velocity pressure of two points, work input, etc. Solve for velocity out and use Q=V X A where A is diameter of pipe and V=velocity out. Q=Flowrate